On Mon 19-06-17 13:43:11, David Rientjes wrote:
> This is a partial revert of commit 338a16ba1549 ("mm, thp: copying user
> pages must schedule on collapse") which added a cond_resched() to
> __collapse_huge_page_copy().
>
> On x86 with CONFIG_HIGHPTE, __collapse_huge_page_copy is called in atomic
> context and thus scheduling is not possible. This is only a possible
> config on arm and i386.
>
> Although need_resched has been shown to be set for over 100 jiffies while
> doing the iteration in __collapse_huge_page_copy, this is better than
> doing
>
> if (in_atomic())
> cond_resched()
>
> to cover only non-CONFIG_HIGHPTE configs.
>
> Reported-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> ---
> Note: Larry should be back as of June 17 to test if this fixes the
> reported issue.
>
> mm/khugepaged.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -652,7 +652,6 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page,
> spin_unlock(ptl);
> free_page_and_swap_cache(src_page);
> }
> - cond_resched();
> }
> }
>
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@xxxxxxxxx. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
--
Michal Hocko
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
